#include <stdio.h>
#include <stdlib.h>

int main(void){
  int T = 0;
  int i = 0;
  int X[100] = {};
  int flag = 0;

  scanf("%d",&T);

  for(i=1;i<=T;i++)
     scanf("%d", &X[i]);

  for(i=1;i<=T;i++){
    if(abs(X[i]-X[i-1]) != 1){
      flag = 1;
      break;
    }
  }
  if(flag == 1)
    printf("F\n");
  else
    printf("T\n");
  return 0;
}